There are many reasons why plants need enough space. If they don’t have enough space to grow, you will eventually run into some problems that, in the worst cases, can cause the plants to die and in the best cases can cause them to stop growing. Both are things you want to avoid, so you absolutely want to make sure your plants have enough space.
Over the years, I have made the mistake of planting in too little space or keeping plants too close to each other many times and I have seen a lot of different consequences of it.
In this article, I explain 11 things that can happen if your plants don’t have enough space, whether that means growing them in a pot that is too small or growing them too close to other plants.
At the end of the article, I explain how you can tell if your plants don’t have enough space and what you can do about it to save them.
1. Plants Produce Less if They Don’t Have Enough Space
If you grow vegetables, fruits, herbs, or other production plants with the purpose of harvesting something you can eat from them, it might be tempting to squeeze a few extra plants into the space you have for them. After all, more plants mean more production, right? Not always.
Plants tend to be a lot less productive if they don’t have enough space. There are several reasons for this, but it primarily comes down to getting enough nutrients, water, and sunlight. The less space plants have, the harder it is for them to get what they need, which results in less production.
I get into why plants that don’t have enough space have trouble with nutrients, water, and sunlight later in this article.
There are a lot of other problems with growing plants too close to each other or in too little space and also a lot of other consequences of doing so, which causes the plants to produce less and even grow a lot less than otherwise, which is my next point.
2. The Plants Grow Slower and Will Eventually Stop
When plants don’t have enough space, they will start growing slower and slower and eventually stop growing at all over time.
If you are growing houseplants or other ornamental plants that you don’t mind keeping relatively small, then planting them close to each other or in small spaces might be just fine.
If you are growing vegetables, fruits, herbs, or other production plants, however, you definitely want to give them enough space so they can grow to their full size to get the most out of them.
That said, there are certain plants where some people prefer smaller plants but more of them. For example, I like to grow lettuce very densely sometimes to get a lot of small plants rather than a few large ones.
The primary reason why overcrowded plants or plants in small spaces grow slower or stop growing altogether is that the roots run out of space. I get into this now.
3. The Roots Run Out of Space
The primary reason why plants growing in small spaces or growing too close to each other stop growing or don’t produce much (or any) fruit is that their roots run out of space.
As the roots grow, there will be less and less excess space in the ground. If you grow many plants very close to each other, they will run out of space even faster. When the roots run out of space, they can no longer obtain nutrients or water, which causes them to stop growing.
If rootbound plants (which is when the roots run out of space) aren’t moved to a place with more space, such as a larger pot or a different spot in the garden, they will eventually die since they can’t get what they need.
4. Too Much Competition for Nutrients in the Soil
If you sow a lot of seeds or place a lot of plants close to each other, they are going to be competing for the same nutrients, which causes the soil to be depleted of nutrients more quickly.
This can mean that you need to use more fertilizer than expected to keep the soil nutritious enough for the plants. This brings another risk which is overfertilization, which can also kill plants.
5. Too Much Competition for Water Plus Risk of Overwatering
Just like they compete for nutrients, overcrowded plants compete for water.
This means that you probably have to water your plants more than you otherwise would if there are a lot of them very close to each other. This can increase the risk of issues such as overwatering and mold in some of the plants since not all of them will need the same amount of water.
The fact that some of the plants can become overwatered before other plants even get the water they need can lead to several other issues, including mold, which can spread easily to other nearby plants. I get into this in more detail at point number 9 in this article.
6. Plants That Are Too Close Together Can Block Sunlight
When you sow seeds or seedlings, it can be very tempting to place them close to each other to get as many plants as possible. An issue with that, however, is that when the plants get bigger they begin to block the sunlight from reaching some of the other plants.
The closer plants are, the more sunlight they will block and prevent from reaching other plants. This will most likely cause a few of the plants to become relatively large and the rest to stay very small since they weren’t as lucky in the who-gets-the-sunlight game.
In this case, the large plants might do okay in the beginning, but since the small plants are still there and still growing (at least a little bit), the plants will all fight for space for the roots underground, which I talked about earlier in this article. Ultimately this leads to none of the plants reaching anywhere near their full potential when it comes to growth and production.
7. Plants That Don’t Have Enough Space Might Not Flower
Another consequence of not giving your plants enough space is that they might not flower. This is because plants need good enough conditions when it comes to nutrients, water, sunlight, and spacing to flower properly.
This might not be a problem for you if you are growing house plants or other ornamental plants that you don’t necessarily want to flower, but if you grow vegetables, fruits, or other production plants, you usually want them to flower since that is a key step in the process.
8. Poor Airflow Leads to Humid Conditions
If plants don’t have enough space around them and especially if there are a lot of them very close to each other, the air will not be able to flow between the plants nearly as well as if they had more space.
Poor airflow leads to humid conditions which increase the risk that diseases and pests will attack the plants. The risk of mold especially increases in plants that grow very close together since mold thrives in humid conditions.
This is a very important reason why plants should get enough space. It can be tempting to grow them close together, but if that significantly increases the risk of losing all of them, it is definitely not worth it.
9. Mold Spreads Much Faster Between Plants Near Each Other
As I wrote above, overcrowded plants are more likely to develop mold since the airflow between the plants will usually be poor, which leads to humid conditions.
A very real consequence of overcrowding plants is that mold spreads very easily. Especially in humid conditions, so you have to keep a very close eye on your plants and avoid overwatering them.
10. Pests and Diseases Can Spread Between Overcrowded Plants
Just like mold, when one or some of your overcrowded plants become infected or gets attacked by something, there is a very high chance it will spread to nearby plants.
Placing lots of plants very close together makes it very easy for pests or diseases to spread. This is especially true if you grow a lot of the same type of plant very close together since they are vulnerable to the same types of pests and diseases.
11. It Is Harder to Identify Issues With Overcrowded Plants
Lastly, here is a thing I didn’t think about until long after I had made the mistake of planting too many plants in too little space and that is that the dense canopy can make it really hard to identify issues with some of the plants or the soil.
If an issue with one or some of the plants or the soil isn’t taken care of, the risk that it spreads to all the plants becomes higher and higher.
How to Tell if Plants Need More Space (And How to Save Them)
There are a lot of potential problems to deal with if your plants are growing in too little space or too close to each other. The most effective thing you can do to help your plants is to either move them somewhere where they have more space or thin them out if there are too many in too little space.
But how can you tell if your plants need more space? I’ll tell you.
The most important thing to look out for when determining if plants need more space is that there should always be some air around all of your plants, like in the photo above.
If you have trouble figuring out how much space plants need in general, I recommend reading this article about five different gardening methods that work well in small spaces. It also focuses on how to get as much as possible out of a small space without overcrowding plants.
As I wrote earlier in this article, proper airflow is crucial for almost all plants since it reduces the risk of a lot of problems including mold, pests, and diseases.
Choosing the right plants for your space is, of course, also extremely important to avoid overcrowding them. That’s why I wrote this article (link opens in new tab) where I cover 43 plants you can grow in small spaces. The article is based on my own experience with small space gardening, but also on input I got from 6 experts.
Another thing to look out for is stunted growth. This happens if the roots underneath the ground are running out of space, which usually happens eventually for plants that are too close to each other.
There are more reasons why plants stop growing, so it doesn’t always (at all) mean that the plants have run out of space. A lot of plants grow a lot slower or stop entirely when they produce fruit since the energy goes toward fruit production instead of growth.
The easiest way to save an established plant that is running out of space is to move it, either to a larger pot or container or somewhere else in the garden. You have to be careful when you do this though, as you can easily damage the plants.
If your plants are still very young or in the seedling stage, the easiest way to make sure they have enough space is to simply thin them out by removing the excess plants like I had to do for these.
This is a photo of some spinach seedlings I had a few years ago and as you can see, I sowed way too many seeds in too little space.
I decided to thin them out by simply pulling some of them out of the ground and discarding them. I did that to make sure the ones I left in the soil had enough space to grow and produce some tasty spinach for me.
I have written another article (here) where I go into more detail about how to tell if plants are overcrowded and how to save them. If that is relevant to you, I highly recommend reading it.
Lastly, I want to mention that while plants, of course, need enough space, growing plants in small spaces is not all bad (as long as they have enough space). I have written this article where I explain all the advantages and disadvantages of small-space gardening, which I learned from growing a lot of vegetables, berries, herbs, flowers, and more on a small balcony I had in a place I lived a while ago.
